In an increasing number of liquid crystal panels, a technology of forming a color filter on array (COA) on an array of thin-film transistors (TFT) is used to improve the quality of image on a curved surface of a liquid crystal panel or simplify a structure of an upper plate, e.g., simplify a structure of an over coat (OC) of the upper plate of an In-Plane Switching (IPS) liquid crystal mode.
In the related art, a technology of manufacturing an array of a COA structure of the liquid crystal panel is as follows: after the manufacturing of gate electrodes, source electrodes and drain electrodes in a traditional COA structure are completed, a procedure of forming a first insulating layer is carried out; and then, steps of coating, exposing and developing a color filter layer (including a red photoresist, a green photoresist and a blue photoresist) are completed; and if the liquid crystal panel uses a white, red, green and blue (WRGB) technology, steps of coating, exposing and developing a transparent photoresist layer are also needed. A procedure of forming a second insulating layer is conducted after a structure of the color filter layer or the transparent photoresist layer is formed. Then a photoresist layer is coated, exposed using a mask with through holes, and developed and etched to remove the first insulating layer and the second insulating layer corresponding to the through holes and located above the array. The photoresist layer is removed to continue a process of manufacturing pixel electrodes (PEs).
In the industry of liquid crystal display (LCD), the production cost of TFT LCD remains large due to the complex processes and large device investment. With fierce market competition, reduction of the production cost of a display screen has become an inevitable development direction of the industry of flat-panel display. Therefore, there is need to develop a new technology of producing display panels, so as to reduce the production cost and increase the production efficiency.